Aramex Couriers — Aramex charging too much custom duty

Address:	Gurgaon, Haryana, 122001
Website:	Www.Aramex.com

Hi, i am navdeep singh and i have ordered protein suppliment from a uk based website. The total i have paid for my order is 5730 inr (Product amount and free shipping) and then when my product reached india, i started getting mails from aramex regarding submission of kyc documents and authorisation to aramex to pay custom on my behave. Even if i have not given any authorisation, aramex claim that they have already paid the custom duty and asking me to pay 5548 inr as a custom duty which is almost 100℅ of my product value. "that is too much", when i ask them to give me the custom bill they said that they pay custom duty for whole consignment not for the individual parcel so they can't give that.
I am ready to pay the genuine custom duty but right now they are asking for unacceptable amount.
No indian law state that health supplements would be charged 100℅ custom duty. I need a justification on this. My product is still with aramex as they did't try to deliver it yet.